Published: March 22, 2011

WASHINGTON — President Obama worked on Tuesday to bridge differences among allies about how to manage the military campaign in Libya, as airstrikes continued to rock Tripoli. Forces loyal to Col. Muammar el-Qaddafi, however, showed no sign of ending their sieges of rebel-held cities.

Anja Niedringhaus/Associated Press

On a day when two United States airmen bailed out over Libya and were rescued after the crash of their fighter jet, Mr. Obama and the leaders of Britain and France stepped up efforts to work out an accord on who would be in charge of military operations once the initial onslaught on Libya’s air defense systems was complete.

Mr. Obama reiterated that the United States would step back from the leading role within days, but he also said it was confronting the complexities of running the military campaign with a multilateral force cobbled together quickly and without a clear understanding among its members about their roles.

The president expressed confidence that the coalition would resolve disagreements over the role of NATO, which had flared in recent days over France’s insistence that the alliance not play a leading role in the operation. NATO now seems likely to provide “command and control” functions, but with a separate authority running the operation, which includes Arab and other non-NATO countries.

“I would expect that over the next several days you will have clarity and a meeting of the minds of all those who are participating in the process,” Mr. Obama said in a news conference in El Salvador, where he was nearing the end of a Latin American trip that has been eclipsed by the military strikes on forces loyal to Colonel Qaddafi.

Even as the Western allies tried to settle management issues, they were still struggling to corral Arab backing for the campaign. Mr. Obama telephoned the emir of Qatar, Sheik Hamad bin Khalifa al-Thani, on Tuesday to nail down his support. So far, Qatar is the only Arab state to offer fighter jets to help enforce a no-fly zone, and there were signs that other Arab states were wavering in their support.

The tension and confusion laid bare the unwieldiness of the coalition — which American officials conceded had been put together on the fly — even four days into the operation, after the coalition had fired 162 Tomahawk missiles and the United States lost its first plane, an F-15E Strike Eagle, which crashed near Benghazi after mechanical troubles. Its two-member crew had minor injuries but was rescued.

“This is complicated,” Defense Secretary Robert M. Gates said to reporters with him in Moscow. “This command-and-control business is complicated. We haven’t done something like this, kind of on the fly before. So it’s not surprising to me that it would take a few days to get it all sorted out.”

At least three bomb blasts were heard in Tripoli Tuesday evening as flares from Libyan antiaircraft guns arced across the sky. Attacks by pro-Qaddafi forces were particularly intense in the western cities of Zintan and Misurata, where snipers and artillery have killed dozens over the past five days and wounded scores more, a rebel spokesman said.

Colonel Qaddafi made a brief but defiant appearance on Libyan television Tuesday night, appearing at what reporters were told was his Tripoli residence to denounce the bombing raids and pledge victory. “I am here. I am here. I am here,” he shouted from a balcony to supporters waving green flags.

Adm. Samuel J. Locklear III, an American officer who is the tactical commander of the mission, said that his intelligence reports confirmed that Colonel Qaddafi’s forces were attacking civilians in Misurata.

The admiral, who briefed reporters at the Pentagon by telephone on Tuesday afternoon, did not say whether there had been a response yet, but said, “We are considering all options.”

A rebel spokesman, reached by satellite phone in Misurata, said he had not seen any evidence of airstrikes there against the Qaddafi forces, which continued to shell the city and threaten residents with sniper fire.

“They now control all the way to the town center, and they have put snipers on the rooftops along the way,” said the rebel spokesman, Mohamed, using only his first name to protect his family.